Peristaltic pump

ABSTRACT

A peristaltic pump including a readily replaceable tube with nipples affixed to the tube ends and which fit and are anchored by sockets in the pump casing, and a rotor disk provided with a tube guide for guiding a replacement tube into operative position in the casing.

United States Patent 1 Stenner [4 1 Sept. 4, 1973 PERISTALTIC PUMP [22]Filed: Dec. 20, 1971 [21] Appl. No.: 209,605

[52] US. Cl. 417/477, 226/91 [51] Int. Cl. F04b 43/08, F04b 43/12, F04b45/06 [58] Field of Search 417/474, 475, 476, 417/477, 63; 418/45;226/91 [56] References Cited UNITED STATES PATENTS 3,502,034 3/1970Pickup 417/477 X 3,227,092 1/1966 Clark 417/475 X 2,899,905 8/1959Becher .J..'. 417/476 X 6/1971 lsreeli 417/476 X 4/1969 Hrdina 417/475OTHER PUBLICATIONS Circular for Randolph Company, advertising theirpump. Dated 5/7/62.

Primary Examiner--Car1ton R. Croyle Assistant Examiner-Richard E. IAttorney-George I-l. Baldwin, Arthur G. Yeager et a1.

5 Claims, 6 Drawing Figures PAIENIEW 3.756.752

SHEEI 1 BF 2 INVENTOR A 7' TOR/YE) '1 1 1 .5 i Mm;

PArEmw SHfU 2 0F 2 GUSTAV H. STENNER IN l/E N TOR A TTOR/VE YPERISTALTIC PUMP This invention pertains to peristaltic pumps, andparticularly to pumps useful for feeding chemicals at a controlled rate,such as for feeding liquid chlorine chemicals into swimming pools.

A general object of the invention is to improve the operation, simplifythe construction, and simplify maintenance and repair procedures inperistaltic pumps.

A specific object of the invention is to simplify the replacement of thecompressible pumping tube in a peristaltic pump.

The novel features which are believed to be characteristic of thisinvention are set forth with particularity in the appended claims.

The invention itself, however, both as to its organization and method ofoperation, together with further objects and advantages thereof, maybest be understood by reference to the following description taken inconnection with the accompanying drawings, in which:

FIG. 1 is an end view of the pump element, with the end cover removed,showing the pumping tube arranged for insertion into operative positionin the pump element housing;

FIG. 2 is a similar view showing the tube partially in position;

FIG. 3 is a similar view showing the tube completely installed; I

FIG. 4 is an end view of the cover element for the pump body;

FIG. 5 is a front exploded view of the pumping element housing showingthe cover aligned for attachment to the body portion; and

FIG. 6 is a side elevation of a complete pump unit including theintermittent drive therefor, with certain parts broken away andpartially in section.

As seen in FIGS. 1, 2, 3 and 4, the pump element body 1 includes ahollow cylindrical pumping chamber or cavity portion 2 in which a rotorassembly 3 is disposed. Rotor assembly 3 includes an outer disk 4, ofwhich the outer surface 5 is substantially flush with the outer edge 6of the cylindrical portion 2 of the housing. Mounted to and underlyingthe disk 4 are a plurality of rollers, such as rollers 7 and 8, whichare freely rotatable on pins 9 and 10.

The compressible tube 11 includes a rigid nipple 12 fixedly attached toend 13 of the tube. The nipple 12 comprises a throat or groove portion14 between its outer externally threaded end portion 15 and its innerend portion 16 which is of reduced external diameter, and the nipplenests in a socket generally identified at 17 formed in a boss 18 of thepump element body 1, whereby the discontinuous surfaces of the nippleand the socket include engaged shoulders in a tongue and grooveconnection retaining the nipple, and therefore the tube end 13, frombeing pulled into or pushed outwardly of the pumping chamber.

Disk 4 includes a guide finger or lip 19 bounding an open notch 20 whichextends inwardly into disk 4 from its periphery. In order to position atube 11 in the pumping chamber 2, nipple 12 is inserted into socket 17into such a position that tube end 13 is inwardly of disk 4 and isgenerally aligned with the centers of rollers 7 and 8, with the majorportion of tube 11 extending outwardly through notch 20. As the disk androller assembly 3 is rotated in a counterclockwise direction as viewedin FIG. 1 from its position shown in that figure into the position shownin FIG. 2, tube 11 is guided by lip 19 down into the cylindrical pumpingchamber or cavity 2 of the housing, with the tube passing along throughnotch 20, while roller 7 starts to roll along the tube in the cavity.Continuing rotation of the roller assembly 3 until notch 20 reaches aposition opposite to a second socket 21 then permits the nipple 22,which is affixed to the opposite or output end 23 of tube 11, to beslipped into its respective socket 21 in the body.

The body 1, disk 4 and cap or cover 25 are each formed of a hard,transparent synthetic plastic material, whereby the tube is visiblethrough the disk as it is being fed into position, as shown in FIG. 2,for example, and the interior of the pump can be seen during operationthereof. Leakage from the tube into the pumping chamber is thus visuallydetectable, and condition of the tube can be determined withoutdisassembling the pump. Tube 11 is also transparent but is of a softsynthetic plastic material so as to be compressible into flattened shapeby the rollers. Flow of liquid through the tube, during operation of thepump, is readily witnessed through the body 1, or through cap 25 anddisk 4, and through the tube wall.

The inner face 26 of cover 25 is provided with two bosses 27 and 28which are received, respectively, into sockets 17 and 21. Each of thesebosses has an end surface such as shown at 29 on boss 27, for engagementwith the portion of the tube end and the nipple portion which lie withinthe socket thereby to retain the-nipples securely in their respectivesockets when the cover is in place.

Centrallywithin the cover is a projection 30 containing a sleeve bearing31- for a drive shaft 32 keyed to rotor assembly 3 by means of keys 33.

Turning now to FIG. 6, it will be seen that rotor assembly 3 comprises abarrel 34 carrying outer disk 4 and inner disk 35 at its opposite ends.The barrel and disks are attached rigidly together, such as by the useof a suitablecement. Rollers 8 and 7, preferably of hard phenolicmaterial, are mounted for free rotation between the disks. Pin 9 isshown, for example, having its ends embedded in the respective disks andmounting roller 7.

Shaft 32 is rotatable in bearing 31 and in sleeve bearing 37 housed ininner wall portion 38 of the pump body 1. The shaft has an enlargedportion 39 extending into a-roller over-running clutch 40 mounted in amain support housing 41. The clutch includes rollers or bearing needles42 surrounding the shaft and permitting free rotation thereof in onedirection in the manner of a needle hearing. The rollers or needles arearranged in individual eccentric cavities in the clutch, and, upon veryslight rotation of the shaft in the opposite direction, the needles jambetween the shaft and the fixed clutch housing 43 thereby preventingrotation of the shaft in said opposite direction. The shaft 32 mounts adrive disk 44 having a plurality of openingsfor receiving a pin 45 of anintermittent drive arrangement 46 of the type shown and described in US.Pat. No. 2,975,719 issued Mar. 21, 1961, to Samuel Kaufman.

The intermittent drive includes an adjustment knob 47 for adjusting arm48, a spring loaded follower 49 in cluding a sensing portion 50 fortraversing groove 51 V and carrying pin 45. Pin 45 and follower 49 arecarried on a gear wheel 52 which is driven by a motor 53. A flexibleland member 54 fills more or less of groove 51 and serves toforce'portion 50 generally outwardly of the groove, and thus todisengage pin 45 from disk 44 through a portion of each revolution ofgear wheel 52.

While pin 45 is drivingly engaged with disk 44, shaft 32 is rotated withgear wheel 52. When pin 45 is disengaged, pressure in the tube 1 l onthe output sides of the pump rollers tends to rotate shaft 32 in theaforementioned opposite direction resulting in jamming of the clutchrollers 42 on the shaft and thereby preventing such opposite rotation ofthe shaft.

It will be noted that cover 25 is attached to body 1 by self tappingscrews or bolts 55 and that the body is similarly attached to supporthousing 41 by screws or bolts 56.

lt will be understood that the nipples 12 and 22 are attached torespective external inlet and outlet conduits for pumping of fluidsthrough the tube 11. In replacing the pump tube, the cover 25 isremoved, nipples l2 and 22 are detached from the external inlet andoutlet conduits, and the motor is operated sufficiently to bring notch20 into alignment with socket 14. The nipple 12 is now pulled out of itssocket so that the tube extends through notch 20. With continuedoperation of the motor, and with a pull exerted on the nipple 12, thetube is gradually fed out of the chamber 2 until the notch 20 alignswith socket 21, at which time nipple 22 is removed. A new tube 1 l isreplaced by a similar procedure, first aligning notch 20 with socket 17and inserting nipple 12 into this socket with the tube extending fromits end 13 outwardly through the notch. As rotor is now rotated, thetube is gradually fed into chamber 2 by lip 19 until the notch reachessocket 21, at which time nipple 22 is slipped into this socket.Replacement of cover 25 and reattachment of the nipples to the externalconduits completes the replacement procedure.

While the invention has been described with respect to a certainspecific embodiment, it will be appreciated that many modifications andchanges may be made by those skilled in the art without departing fromthe spirit of the invention. It is intended, therefore, by the appendedclaims to cover all such modifications and changes as fall within thetrue spirit and scope of the invention.

What is claimed as new and what it is desired to secure by LettersPatent of the United States is:

1. In a peristaltic pump comprising a pump body with an internalgenerally cylindrical wall between an open front side to a back side ofsaid body, said wall defining a generally cylindrical pumping chamber insaid body, said body comprising a tube anchoring socket communicatingwith said chamber and an opening through said body into said chamber andsaid opening being laterally exposed through the front side of saidbody, said opening being peripherally displaced around said wall fromsaid socket, a pumping tube, anchoring means at one end of said tube foranchoring engagement in said socket, a rotatable shaft coaxial with saidcylindrical chamber, a tube compressing element carried by said shaftdisposed within said chamber for traversingly compressing said tubeagainst said wall upon rotation of said shaft, tube inserting guidemeans fixed to said shaft and rotatable therewith, said guide meanscomprising a finger portion extending generally radially from said shafttoward said wall and disposed between said socket and said open frontside, said finger portion being adapted and arranged upon rotation ofsaid shaft to feed said tube, when its said anchoring means is soanchored in said socket, into said chamber along said wall from saidsocket to said opening.

2. The combination according to claim 1 wherein said opening comprises asecond socket and the other end of said tube is provided with anchoringmeans for anchoring engagement therein.

3. The combination according to claim 2 wherein said anchoring means andsockets include interfitting surfaces forming respective tongue andgroove connections for retaining said tube ends against longitudinalmovement therein.

4. The combination according to claim 1 wherein said guide meanscomprises a disk of which said finger portion comprises a lip of atube-passing notch extending into the peripheral edge portion of thedisk, and wherein said disk mounts said element and at least oneadditional tube compressing element.

5. The combination according to claim 4 wherein said body is providedwith transparent front cover means removably attached thereto andwherein said disk is transparent.

1. In a peristaltic pump comprising a pump body with an internalgenerally cylindrical wall between an open front side to a back side ofsaid body, said wall defining a generally cylindrical pumping chamber insaid body, said body comprising a tube anchoring socket communicatingwith said chamber and an opening through said body into said chamber andsaid opening being laterally exposed through the front side of saidbody, said opening being peripherally displaced around said wall fromsaid socket, a pumping tube, anchoring means at one end of said tube foranchoring engagement in said socket, a rotatable shaft coaxial with saidcylindrical chamber, a tube compressing element carried by said shaftdisposed within said chamber for traversingly compressing said tubeagainst said wall upon rotation of said shaft, tube inserting guidemeans fixed to said shaft and rotatable therewith, said guide meanscomprising a finger portion extending generally radially from said shafttoward said wall and disposed between said socket and said open frontside, said finger portion being adapted and arranged upon rotation ofsaid shaft to feed said tube, when its said anchoring means is soanchored in said socket, into said chamber along said wall from saidsocket to said opening.
 2. The combination according to claim 1 whereinsaid opening comprises a second socket and the other end of said tube isprovided with anchoring means for anchoring engagement therein.
 3. Thecombination according to claim 2 wherein said anchoring means andsockets include interfitting surfaces forming respective tongue andgroove connections for retaining said tube ends against longitudinalmovement therein.
 4. The combination according to claim 1 wherein saidguide means comprises a disk of which said finger portion comprises alip of a tube-passing notch extending into the peripheral edge portionof the disk, and wherein said disk mounts said element and at least oneadditional tube compressing element.
 5. The combination according toclaim 4 wherein said body is proviDed with transparent front cover meansremovably attached thereto and wherein said disk is transparent.